JP2000153179A - Method and apparatus for generating anion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate anions effectively in an external space by a simple structure. SOLUTION: In an anion generator having a photoelectron releasing material 4, an electrode 6 for an electric field, and an irradiation source 5 for irradiating the material 4 with ultraviolet rays and/or radiations on a gas inlet side and has a charged particle collecting member 7 on a gas outlet side, the member 7 is formed from a passage C1 in which a part of a gas passage does not have an electric field and can be an electrode plate or an electret material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the generation of negative ions, and more particularly, to a method and an apparatus for generating negative ions by irradiating a photoelectron emitting material with ultraviolet rays and / or radiation.

[0002]

2. Description of the Related Art Conventionally, as a method of generating negative (negative) ions, a method of applying a negative high voltage to an electrode has been known. However, this method has problems of generation of ozone and generation of fine particles. Was. Further, since high voltage electricity is used, there is a problem in safety. For this reason, the appearance of a new method that has solved these problems has been expected. That is, in the field of a comfortable working space (amenity), there is a demand for a comfortable living space that is ozone-free and does not impair the metabolic function and physiological function of the living body. In addition, in the field of advanced industries such as semiconductors and liquid crystals, an ozone-free and electrically stable (low potential) ultra-clean space (work space) free of fine particles is required.

In the current working space, both positive and negative ions are present, but there are many cases where the number of positive ions becomes excessive due to the contents of work and natural phenomena. One of the causes is
Negative ions have higher mobility (moving speed is faster) than positive ions, so negative ions move faster and are consumed. As a result, it is considered that positive ions become excessive. (1) Negative ions are extremely reduced in a closed room or working space. (2) Normal floating fine particles are positively charged by airflow. (3) In a clean room of a semiconductor factory, there are many positively charged fine particles and air molecules due to space discharge by a high-voltage power supply and molecular friction in a work place. Such an atmosphere causes a decrease in product yield (eg, an increase in particle contamination due to generation of static electricity). Also, it is said that a person changes their physical condition due to a decrease in negative ion concentration (becomes unwell).

[0004] That is, the human body is formed of countless cells, each cell is wrapped in cells, and the cells absorb nutrients through their membranes and excrete waste products to perform activities. I have. These cells have positive ions on the outside and negative ions on the inside, and when the amount of negative ions decreases and the amount of positive ions becomes excessive, a phenomenon occurs in which it becomes difficult to absorb nutrients and excrete waste products. It is thought to cause a decline in function. Under such circumstances, the present inventors have previously proposed a negative ion generation method using a photoelectron emitting material. The proposed invention is illustrated below. (1) JP-B-8-10616, (2) JP-A-7-106
57643, (3) Japanese Patent Application Laid-Open No. 7-293939 These proposed methods and apparatuses are effective depending on the place of use, but depending on the place of use, it is necessary to further improve and improve the practicality. . Improvements of these methods will be described.

FIG. 5 is a schematic configuration diagram of an air purifier (comfort air generator) for removing particles and generating negative ions (Japanese Patent Application Laid-Open No. 7-293939). The air purifier includes a fan 2 for performing suction and discharge of air, a coarse filter 3, a photoelectron emission material 4-1, an ultraviolet lamp (sterilization lamp) 5-.
1. Photoelectron emission electrode 6-1; charged particle collecting electrode plate 7
A photoelectron charging / collecting part (A) composed of photoelectrons,
A negative ion generator (B) comprising a reticulated photoelectron emission material 4-2, an ultraviolet lamp (sterilization lamp) 5-2, and a photoelectron emission electrode 6-2 is provided at the rear. Each operation will be described. The coarse filter 3 collects coarse particulate matter in the air. Particulate charging / collecting unit (A)
Is a photoelectron emission material 4-1 under an electric field (100 V / cm).
Is irradiated with ultraviolet rays from an ultraviolet lamp 5-1 to generate photoelectrons, and the photoelectrons charge the fine particles;
The charged fine particles are collected and removed by the charged particle collecting electrode material 7. The electrode 6-1 is for forming an electric field between the photoelectron emitting material (negative) 4-1 and the electrode (positive) 6-1.

The negative ion generator (B) irradiates the reticulated photoelectron emitting material 4-2 with ultraviolet rays from an ultraviolet lamp 5-2 under an electric field to generate photoelectrons, and the photoelectrons generate negative ions. Is generated. Numeral 8 denotes inlet air, and numeral 9 denotes negative ion-enriched dust-free air. With such a configuration, the negative ion-enriched air 9 needs to be provided with a separate negative ion generator (B) behind the charge / collection unit (A) for the fine particles by photoelectrons. There were problems such as the increase in size, cost, and complexity of maintenance and inspection, and there was room for improvement.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and provides a method and apparatus for generating negative ions capable of effectively generating negative ions in an external space with a simple structure. The task is to

[0008]

According to the present invention, a gas is passed through a space under irradiation of ultraviolet rays and / or radiation through a photoelectron emitting material under an electric field, and then the gas is charged. In the method of generating negative ions passing through a passage for collecting particles, the passage for collecting charged particles is partially a passage having no electric field. Also, in the present invention, a photoelectron emitting material, an electric field electrode, and an irradiation source for irradiating the photoelectron emitting material with ultraviolet light and / or radiation are provided on the gas inlet side, and the charged particle collecting material is provided on the gas outlet side. In the negative ion generator having the above structure, the charged particle trapping material is configured such that a part of the gas passage is formed as a passage having no electric field. In the above-described method and apparatus for generating negative ions, collection of charged particles can be performed using an electrode plate or an electret material.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention has been made based on the following three findings. (1) When the photoelectron emitting material is irradiated with ultraviolet rays and / or radiation under an electric field, photoelectrons are emitted from the photoelectron emitting material, and the emitted photoelectrons are changed to negative ions (Japanese Patent Publication No. Hei 8 (1996)).
-10616, Aerosol Research, Vol. 8, No. 3
No., P239-248, 1993). Since the negative ions (negative ion-enriched gas) are ozone-less, they can be suitably used in various fields. For example, it can neutralize excess positive ions in the semiconductor, liquid crystal and precision machinery industries. In the amenity, that is, the space where the negative ions are enriched, a comfortable feeling (exhilaration) is obtained for the human body. In the food field, it can be used to maintain the freshness of foods and to prevent the growth of fungi.

(2) In the generation of negative ions by photoelectrons (the negative ions are taken out of the apparatus and used), it is preferable to remove particulate matter in advance in order to efficiently generate the particles (Japanese Patent Publication No. 8-10660). And JP-A-7-293939). This is because the released negative ions are collected (consumed) by the coexisting particulate matter. (3) In the use of negative ions, dust-removed negative ion-enriched air is preferable. Therefore, in the method using photoelectrons, in order to perform dust removal and negative ion generation, a dust removal unit using photoelectrons is installed in the front, and then a negative ion generation unit is installed behind (see FIG. 5). On the other hand, a part of the charged particle trapping material (the side where the photoelectron emitting material is installed) in the charging / collecting part of the fine particles using photoelectrons has no electric field (there is no electric field. When a potential is provided, a part of the generated negative ions is released to the outside through the passage.

The emission of the negative ions to the outside of the apparatus is shown in FIG.
This will be described with reference to FIG. The negative ions (e) changed from the photoelectrons emitted from the photoelectron emitting material move under the influence of the electric field and the air current. In FIG. 4, Ve is the velocity vector of the negative ions due to the electric field, Vf is the velocity vector of the negative ions due to the flow, and the negative ions (e) generated from the photoelectron emitting material are at the positions of the generated negative ions, Ve and Vf. Correspondingly, it has velocity vectors as indicated by a _{1 to} a ₃ . That is, negative ions generated behind the photoelectron emitting material are:
The particles move under the strong influence of the flow Vf and are not collected (consumed) by the coexisting particulate matter (the collection probability is low). Will be released. In the present invention, based on this finding, negative ions are generated by setting a part of the collection passage as a passage having no electric field.

Next, each configuration of the present invention will be described in detail. As the photoelectron emitting material, those already proposed by the present inventors can be appropriately used (for example, Japanese Patent Publication No. 6-7490).
No. 9, No. 8-211, No. 7-121369
No., Japanese Patent Publication No. Hei 8-22393). The photoelectron emitting material may be any material that emits photoelectrons when irradiated with ultraviolet light and / or radiation, and the smaller the photoelectric work function, the better. In terms of effectiveness and economy, Ba, S
r, Ca, Y, Gd, La, Ce, Nd, Th, Pr,
Be, Zr, Fe, Ni, Zn, Cu, Ag, Pt, C
d, Pb, Al, C, Mg, Au, In, Bi, Nb,
One of Si, Ti, Ta, U, B, Eu, Sn, P, and W, or a compound or alloy or a mixture thereof is preferable, and these are used alone or in combination of two or more. As the composite material, a physical composite material such as amalgam can be used.

For example, compounds include oxides, borides and carbides, and oxides include BaO, SrO, and Ca.
_{O, Y 2 O 5, Gd} 2 O 3, Nd 2 O 3, ThO 2, ZrO 2,
Fe ₂ O ₃ , ZnO, CuO, Ag ₂ O, La ₂ O ₃ , Pt
O, PbO, Al ₂ O ₃ , MgO, In ₂ O ₃ , BiO, N
bO, BeO, etc., and borides include YB ₆ ,
GdB ₆ , LaB ₅ , NdB ₆ , CeB ₆ , EuB ₆ , Pr
B _6, include ZrB _2, as a further carbide UC,
ZrC, TaC, TiC, NbC, WC and the like. In addition, brass, bronze, phosphor bronze, an alloy of Ag and Mg (Mg is 2 to 20 wt%), an alloy of Cu and Be (Be is 1 to 10 wt%), and an alloy of Ba and Al are used as the alloy. Alloy of Ag and Mg, Cu and Be
And an alloy of Ba and Al are preferable. The oxide can also be obtained by heating only the metal surface in air or oxidizing it with a chemical.

As still another method, it is possible to form an oxide layer on the surface by heating before use to obtain an oxide layer that is stable for a long period of time. As an example, an oxide film can be formed on the surface of an alloy of Mg and Ag in water vapor at a temperature of 300 to 400 ° C., and this oxide film is stable for a long period of time. . These substances can be used in bulk (solid or plate) or added to an appropriate base material (support) (Japanese Patent Application Laid-Open No. Hei 3-1086).
No. 98). For example, it can be added to the surface of or near the surface of the ultraviolet ray transmitting substance (Japanese Patent Publication No. 7-93098). The method of addition may be any method as long as photoelectrons are emitted by irradiation of ultraviolet rays and / or radiation.

[0015] For example, a method of coating onto a glass plate for use, as another example, a method of embedding near the surface of a plate-like material, or a method of coating on a plate-like material and further coating another material thereon And a method of using a mixture of an ultraviolet-transmissive substance and a substance that emits photoelectrons. In addition, a method of adding in a thin film shape, a method of adding in a net shape, a linear shape, a granular shape, an island shape, a belt shape, or the like can be appropriately used. A method of adding a material that emits photoelectrons can be made by coating or adhering the surface of an appropriate material by a known method. For example, an ion plating method, a sputtering method, an evaporation method, a CVD method, a plating method, a coating method, a stamp printing method, and a screen printing method can be appropriately used.

The thickness of the thin film may be a thickness at which photoelectrons are emitted by irradiation of ultraviolet rays or radiation, and may be 5 to 5,0.
00 °, usually 20 ° to 500 °. The base material can be used in plate, pleated, cylindrical, rod, linear,
There are a net shape, a fiber shape, a honeycomb shape and the like, and the surface shape can be appropriately made uneven to use. Further, the tip of the convex portion may be sharpened or spherical (see Japanese Patent Publication No.
74908). As for the addition of the thin film to the base material, as already proposed by the present inventors, one kind or two or more kinds of materials can be used in a single layer or a multilayer. That is, a plurality of thin films can be used as appropriate (composite) to form a double structure or a multi-layer structure of more than that (Japanese Patent Application Laid-Open No. 4-1522).
No. 96).

The optimum shape, the type of material that emits photoelectrons by irradiation of ultraviolet rays and / or radiation, the method of addition, and the thickness of the thin film are determined by the type, scale, shape, type of photoelectron emitting material, and type of base material. , Electric field strength, how to apply, effects,
Preliminary tests can be conducted as appropriate for economy and other factors. The base material when the photoelectron emitting material is used by being added to the base material,
In addition to the above-mentioned ultraviolet transmitting material, there are ceramics, clays and well-known metal materials. Alternatively, the surface of a light source described below can be coated with the above-mentioned photoelectron emitting material (the light source and the photoelectron emitting material are integrated) (Japanese Patent Laid-Open No. 4-243540). It can also be integrated with a photocatalyst (Japanese Patent Laid-Open No. 9-294).
919).

In this embodiment, the photocatalyst can stabilize the photoelectron emitting material for a long time (can be removed even if there is an influence substance on the photoelectron emitting material) and can remove coexisting gaseous pollutants. Depending on the type and required performance). When photoelectrons are generated by irradiating the photoelectron emitting material with ultraviolet rays and / or radiation, an electric field (electric field) is formed between the photoelectron emitting material and an electrode to be described later. . Therefore, when the photoelectron emitting material is used in addition to a non-metallic base material such as glass or ceramic, ITO is formed on the base material to form a reliable electric field.
Such a conductive substance can be added in advance (Japanese Patent No. 2598730). The strength of the electric field depends on the application, type of device, shape, type of photoemission material, and required performance.
Preliminary tests can be carried out as appropriate to determine. Generally, 0.
It is 1 V / cm to 2 kV / cm.

Next, the electrodes will be described. The electrode is provided on the opposite side of the photoelectron emitting material to effectively generate photoelectrons from the photoelectron emitting material, and forms an electric field between the electrode and the electrode. The electrode material and its shape may be any as long as the electric field can be formed. Any material can be used as long as it does not generate impurities or the like and is a conductive material, and examples thereof include SUS, Cu-Zn, and W. Shapes are plate, pleated, cylindrical, rod, linear, fibrous,
There are a net shape and a honeycomb shape, which can be determined by conducting a preliminary test as appropriate according to the type, shape and scale of the device and the photoelectron emitting material.

Next, an ultraviolet irradiation source will be described. The irradiation source may be one that emits photoelectrons from the photoelectron emitting material by irradiating the aforementioned photoelectron emitting material. In general, mercury lamps, hydrogen discharge tubes, xenon discharge tubes, Lyman discharge tubes, and the like can be used as appropriate. Examples of light sources include germicidal lamps, black lights, fluorescent chemical lamps, and UV-B
There are ultraviolet lamps and xenon lamps. Among them, a germicidal lamp (main wavelength: 254 nm) is preferable. This is because the germicidal lamp is ozone-less and has a germicidal (sterilizing) action. The light source may have an appropriate shape such as a rod shape, a spiral shape, and a box shape.

Irradiation with radiation may be any as long as the photoemission material can emit photoelectrons by the irradiation.
Irradiation can be performed by a conventionally known method. For example, α-rays, β-rays, γ-rays and the like are used as the radiation, and radioactive isotopes such as cobalt 60, cesium 137, and strontium 90, or radioactive waste produced in a nuclear reactor and appropriate radioactive wastes are used as irradiation means. A method using a processed radioactive material as a radiation source, a method using a nuclear reactor as a direct radiation source, a method using a particle accelerator such as an electron beam accelerator, and the like are used.

Next, a description will be given of charged particles for collecting and removing charged particulate matter and a collecting material (dust collecting material) which are features of the present invention. The trapping material is charged at a charged part of the particulate matter by a photoelectron in front of the trapping material.
In addition to the purpose of removal, in the present invention, by providing a passage having no electric field in a part thereof, the role of passing generated negative ions from the photoelectron emission material of the charged portion (emission to the outside of the device) is provided. Add The passage having no electric field is a space in which no electric field exists. That is, the collecting material may be any material that can reliably collect the charged particulate matter and allow negative ions to pass through a part of the material, and any well-known charged fine particle collecting material can be used.

Dust collecting plate (electrode plate) in a usual charging device Dust collecting electrode Various electrode materials and an electrostatic filter system are generally used. However, a collecting portion itself such as a steel wool electrode or a tungsten wool electrode forms an electrode. The constituent wall-shaped structure is also effective. Electrec materials can also be suitably used. Of these, the electrode plate and the electret material are preferable because they can be easily implemented. The position of the passage having no electric field according to the present invention is not particularly limited as long as negative ions generated from the photoelectron emitting material can exit to the outside. You can make a test and decide. In addition, as the material of the passage having no electric field according to the present invention, a conductive material such as a well-known metal material or a material obtained by coating a metal on a plastic can be used.

[0024]

The present invention will be described below in more detail with reference to examples. Embodiment 1 FIG. 1 is a schematic configuration diagram showing a household air purifier (comfortable air generator) 1 which is a negative ion generator of the present invention for removing particulate matter and generating negative ions. The air purifier of FIG. 1 includes a fan 2 for sucking and discharging air, a coarse filter 3, a photoelectron emitting material 4, an ultraviolet lamp (sterilizing lamp).
5. Photoelectron emission electrode 6 and charged particle collection electrode material 7 comprising photoelectron charge / collection part (A). Each operation will be described. Coarse filter 3
Is for collecting coarse particulate matter in the air.
The charging / collecting part (A) of the fine particles is under an electric field (100 V / c
In step m), the photoelectron emission material 4 is irradiated with ultraviolet rays from an ultraviolet lamp 5 to generate photoelectrons, and the photoelectrons are used to charge the microparticles.
To collect and remove.

[0025] Here, the charged particle collection electrode material 7, as shown as a partially enlarged view in FIG. 2, the collecting unit b ₁ of the charged particles with an electric field for collecting charged particles, adjacent its no passage c ₁ field is provided, negative ions e ₁ is released 10 to the outside of the air cleaner 1 passes from passage c ₁ in. That is, the negative ion-enriched air 12 from which dust has been removed is released from the air purifier 1. 1 and 2, reference numeral 11 denotes dust-removed air in which the particulate matter 13 is charged by photoelectrons and is removed by the charged particle collecting electrode member 7. Next, charge the fine particles
Details of the operation of the collection section (A) will be described with reference to FIG. When the photoelectron emitting material 4 is irradiated with ultraviolet light from an ultraviolet lamp (5 in FIG. 1) in an electric field, the photoelectron emitting material 4
Photoelectrons are emitted, and the emitted photoelectrons are negative ions e ₁ and e ₂
Changes to

Here, the negative ions e ₂ generated from the entrance to the center of the charging / collecting section (A) (from the entrance to the exit of the photoelectron emitting material 4) are positioned as shown in FIG. The particles (non-living particles, living particles) 13 existing in the space are charged while moving in the direction of the electrode 6 under the influence of the electric field and the flow.
The charged fine particles charged in this manner are collected by a charged particle collecting portion b ₁ having an electric field of the rear charged particle collecting electrode material 7.
Is collected and removed at On the other hand, negative ions e ₁ generated at the exit portion of the photoelectron emitting material 4, to the action of an electric field, so that under the strong action of the flow progression (upward) than the no path field (c _1), the outer It is released 10 to. In the above, the electrode 6 is composed of a photoelectron emitting material (negative) 4 and an electrode (positive) 6.
It is for forming an electric field between them. B ₂ in FIG.
Portion having a positive electrode for a charged particle collection which is charged with negative ions, c ₂ denotes an electrode which does not give an electric field (ground electrode).

With this air purifier 1, indoor contaminated air (particle concentration of 0.5 to 1.0 mg / m ³ ) is reduced to 0.05%.
mg / m ³ or less, and the negative ion concentration is 2,000 to
10,000 air / ml of fresh air 12 are obtained. Since the fresh air 12 uses an ultraviolet lamp (germicidal lamp), biological particles are also collected and sterilized, and it is safe (ozone-free and high amenity) high-quality air.
It is a feature of the present invention that such high quality air can be obtained. 2, the same reference numerals as those in FIG. 1 indicate the same meanings, and the arrows in FIGS. 1 and 2 indicate the direction of the flow (movement) of the airflow or the negative ions. In this example, the ultraviolet lamp 5 is a germicidal lamp having a main wavelength of 254 nm, the photoelectron emitting material 4 is a photocatalyst (TiO ₂ ) to which Au is added, and the charged particle collecting electrode material 7 is a plate. SUS material, part of which has a path without electric field as shown in FIG.
Is a reticulated SUS material. The ratio of c _{1 to} b ₁ is
In this example, the length is 1: 0.1.

Embodiment 2 FIG. 3 shows a transfer apparatus having a particle removing and negative ion generating (dust-removed negative ion-enriched air) apparatus 1 installed in a class 1,000 clean room. The apparatus 1 discharges negative ions e ₁ to a transfer device 17 in a clean room (for static elimination) to create an electrically stable space. The apparatus 1 includes a fan 2 that sucks air of class 1,000 in a clean room and discharges the purified (dust-removed) negative ion-enriched air 12 obtained by the apparatus 1.
Charge of fine particles by photoelectrons comprising a coarse filter 3, a photoelectron emission material 4, an ultraviolet lamp (germicidal lamp) 5, a photoelectron emission (extraction) electrode 6, and a charged particle collection electrode material 7.
It consists of a collecting part (A).

Each operation will be described. The coarse filter 3 collects coarse particulate matter in the air due to dust and the like from the fan 2. The fine particle charging / collecting section (A) generates photoelectrons by irradiating the photoelectron emitting material 4 with ultraviolet rays from the ultraviolet lamp 5 under an electric field (5 V / cm), and charges the fine particles 13 with the photoelectrons. The charged fine particles are collected and removed by the charged particle collecting electrode material 7. Reference numeral 14 denotes a reflecting surface for efficiently irradiating the photoelectron emission material 4 with ultraviolet rays from the ultraviolet lamp 5, and 15 denotes a quartz glass window. Here, the charged particle collecting electrode material 7 is
And collecting part b ₁ and no passage c ₁ field of charged particles is provided with as the electric field of FIG. 2, passes negative ions e ₁ from the passageway c _1. That is, in the photoelectron emitting material 4,
When ultraviolet light is irradiated from an ultraviolet lamp under an electric field, photoelectrons are emitted from the photoelectron emitting material 4 and the emitted photoelectrons are changed into negative ions e ₁ and e ₂ .

Here, the negative ions e ₂ generated from the entrance to the center of the charging / collecting section (A) (from the entrance to the exit of the photoelectron emitting material 4) are located at the position, The particles (non-living particles, living particles) 13 existing in the space are charged while moving in the direction of the electrode 6 under the influence of the electric field and the flow.
The charged fine particles charged in this manner are collected by a charged particle collecting portion b ₁ having an electric field of the rear charged particle collecting electrode material 7.
Is collected and removed at On the other hand, the negative ions e ₁ generated at the outlet of the photoelectron emitting material 4 are strongly affected by the flow of the electric field and travel (downward), so that the negative ions e ₁ are outside the passage (c ₁ ) having no electric field. Released to The purified negative ion-enriched air 12 thus obtained is supplied to the transfer device 17, and the glass substrate 16 during transfer has a potential of 3,000 to 3,500 V before static elimination (position D). However, the voltage drops to 10 V or less after static elimination (position E).

With the present apparatus 1, as for the clean room air 8 of class 1,000 containing many positive ions, clean air 12 of class 1 (number of particles in 1 ft ³ ) or less having a negative ion concentration of 5,000 / ml can be obtained. . The clean air 12
Is ozone-less, high-quality, negative-ion-enriched air that has been dedusted to class 1 or less, and is a feature of the present invention. In FIG. 3, the same reference numerals as those in FIGS.
The arrow in indicates the direction of the flow of air or the flow (movement) of negative ions. In this example, the ultraviolet lamp 5 is a germicidal lamp having a main wavelength of 254 nm, and the photoelectron emitting material 4 is a photocatalyst (T
iO ₂ ) to which Au is added, the charged particle collecting electrode material 7 is a plate-shaped SUS material, a part of which has a passage without an electric field as shown in FIG. 2, and the electrode 6 is a meshed SUS material. Material.

Example 3 An air purifier having the structure shown in FIG. 1 (FIG. 2) was installed in a room of 12 m ³ , and a photoelectron emitting material was irradiated with ultraviolet light under an electric field to determine the concentration of negative ions and the concentration of fine particles in the room. Examined. Also,
To examine the effectiveness of negative ions, the generated air was exposed to strawberries and freshness retention was examined. Size of air purifier and air volume; 30 × 30 × 60cm,
0.5 m ³ / min, UV lamp; germicidal lamp (main wavelength: 254 nm), photoelectron emission material, photocatalyst (TiO ₂ ) with Au added by sputtering

Photoelectron emission electrode: wire mesh SUS, 1
00V / cm Charged particle trapping material: plate-shaped SUS, as shown in FIG. 2, having a passage structure without an electric field at both ends (a SUS plate at ground potential) (the electric field portion is 800 V / cm). FIG.
The ratio of c ₁ to ₁ is 1: 0.1 in length. Negative ion concentration meter; ion tester (0.4 cm ² /
With electric mobility of VS or more) Fine particle concentration;

Results (1) Negative ion concentration and fine particle concentration

[Table 1] For comparison with the present invention, in the air purifier shown in FIG. 1 (FIG. 2), the charged particle collecting material 7 has an electric field (800 V) over the entire surface.
/ Cm), and the generated negative ion concentration was similarly examined. The result is that the generated negative ion concentration is 10 to 10
0 / ml, and generation of negative ions by the air purifier of this comparative example was not recognized.

(2) Preservation of Freshness of Strawberry As a freshness preserving effect, the number of days at which mold was observed at 5 ° C. was examined. Table 2 shows the results. For comparison with the present invention shown in Table 2, in the air purifier shown in FIG. 1 (FIG. 2), the charged particle collecting material 7 has an electric field (800 V /
cm), and exposure was similarly measured for freshness retention. The results are shown in Table 2 as comparative examples.

[Table 2] The effectiveness of the negative ion-rich sterilized air obtained by this air purifier was examined by spraying negative ion air onto the agar medium, and cultivating various bacteria, and comparing it with the case where no air was blown. No colonies appeared on the sprayed agar medium, but 1 colony was found on the unsprayed agar medium.
5/10 cm ^{2 were} produced. In the above description, air has been described, but a gas other than air, for example, N ₂ , A
The present invention can be similarly carried out using any gas such as r.

[0036]

As described above, a photoelectron emission material, an electrode for an electric field, and a charged particle collecting material are provided. When the photoelectron emission material is irradiated with ultraviolet rays and / or radiation to generate negative ions, By providing a path having no electric field in a part of the trapping material, the following effects can be obtained. (1) The particulate matter is removed (dust removed) by photoelectrons,
At the same time, a gas rich in negative ions (clean, clean negative ions) was obtained. (2) Only one set (one set) of photoelectron emitting material, ultraviolet and / or radiation irradiation source, electrode for electric field, and charged particle collecting material could remove dust and generate negative ions. That is, the device has been downsized. It is a compact device that can perform both functions of dust removal and negative ion generation at the same time.

(3) As described above, the field of application of particulate matter removal using photoelectrons has been expanded. The practicality has also been improved. (4) The practicality of the next field utilizing negative ions is improved by the above. (A). A field that creates electrically stable spaces. (B). A field that creates a comfortable working space for living organisms that does not impair the metabolic and physiological functions of living organisms. (C). In the field of keeping food fresh and preventing the growth of fungi.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of a negative ion generator of the present invention.

FIG. 2 is an enlarged explanatory view of the vicinity of a charged particle collecting unit in FIG. 1;

FIG. 3 is a schematic configuration diagram of a transfer device provided with the negative ion generator of the present invention.

FIG. 4 is a schematic diagram illustrating the release of negative ions to the outside.

FIG. 5 is a schematic configuration diagram of a known negative ion generator.

[Explanation of symbols]

1: negative ion generator (air purifier), 2: fan,
3: coarse filter, 4: photoelectron emission material, 5: ultraviolet lamp, 6: electrode for photoelectron emission, 7: electrode material for charged particle collection, 8: contaminated air, 10: negative ion flow, 11: dust removal air, 12: negative ion-enriched air, 13: particulate matter, 1
4: reflection plate, 15: quartz glass window, 16: glass substrate,
17: transfer device, A: charging / collecting unit, b ₁ : charging passage,
c ₁ : passage without electric field, e ₁ and e ₂ : negative ions

Claims (4)

[Claims] 1. A method for generating negative ions, comprising: passing a gas through a space under irradiation of ultraviolet light and / or radiation through a photoelectron emitting material under an electric field, and then passing the gas through a passage for collecting charged particles. A method for generating negative ions, wherein a part of a passage for collecting charged particles is a passage having no electric field. 2. The method according to claim 1, wherein the collection of the charged particles is performed by an electrode plate or an electret material. 3. A photoelectron emission material, an electric field electrode, and an irradiation source for irradiating the photoelectron emission material with ultraviolet light and / or radiation on the gas inlet side, and a charged particle collecting material on the gas outlet side. The negative ion generator according to claim 1, wherein the charged particle trapping material has a part of a gas passage formed by a passage having no electric field. 4. The negative ion generator according to claim 3, wherein the charged particle collecting material is an electrode plate or an electret material.